Update 100-redis.md (#1357)

content/roadmaps/101-backend/content/110-caching/101-server-side/100-redis.md

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-# Redis
+# Redis
+
+Redis is an open source (BSD licensed), in-memory **data structure store** used as a database, cache, message broker, and streaming engine. Redis provides data structures such as [strings](https://redis.io/topics/data-types-intro#strings), [hashes](https://redis.io/topics/data-types-intro#hashes), [lists](https://redis.io/topics/data-types-intro#lists), [sets](https://redis.io/topics/data-types-intro#sets), [sorted sets](https://redis.io/topics/data-types-intro#sorted-sets) with range queries, [bitmaps](https://redis.io/topics/data-types-intro#bitmaps), [hyperloglogs](https://redis.io/topics/data-types-intro#hyperloglogs), [geospatial indexes](https://redis.io/commands/geoadd), and [streams](https://redis.io/topics/streams-intro). Redis has built-in [replication](https://redis.io/topics/replication), [Lua scripting](https://redis.io/commands/eval), [LRU eviction](https://redis.io/topics/lru-cache), [transactions](https://redis.io/topics/transactions), and different levels of [on-disk persistence](https://redis.io/topics/persistence), and provides high availability via [Redis Sentinel](https://redis.io/topics/sentinel) and automatic partitioning with [Redis Cluster](https://redis.io/topics/cluster-tutorial).